Hi there I was hoping someone might be able to help me.
I have an AMD A8-6600K APU  with Radion Graphics and 8 gb RAM.. running Windows 10 64 bit personal edition.

It started by telling me the BIOS had changed.. when i booted up, and gave me the option to start up using the best options, which I did. Things had run OK for a month or so, but just the past few days it came on again, only this time the PC started freezing entirely, becomming completely un-responsive. I have had several Blue screens, but  ihave run the blue screen health checker thing in Windows itself and it comes back saying no errors.

I have now done a full recovery of windows and took it all back to basics but it still froze.  Anyone have any suggestions , perhaps a diagnostic tool I could try to see if some hardware is failing? .. I know that sometimes on the blue screens it said it was collecting information on the errors.. but as a novice i have no idea where that information is stored or even how to begin looking at it if i even found it.

Any help would be appreciated. thanks in advance.How old is this PC ? ?
I'd replace the CMOS battery for starters...part # CR 2032...available anywhere...3 Bucks.
Remove all power when replacing...Is this a laptop or a desktop? You did not provide a model name of this PC, you should in the future, just keep that in mind! Just to clarify, does it say the bios has changed every time you start up or did it do it that one time? Does it freeze while in windows all the time or does it freeze while booting up too? If your PC is a desktop it will probably be easier to diagnose if you have failing hardware just by looking in the PC and the parts inside, and interchanging parts. We need more details to proceed. Thanks! Changing the battery like patio suggested is your best bet for starters. Just look up a tutorial online for how to do it.

Hope this helps,
Anthonyhi and thanks, it is a desktop PC about 3 YR old. I changed the battery 2 days ago and haven't seen the Bios message since. however the freezing still continues.  I tried finding the motherboard model but all i found is it is by Gigabyte and the model number says "to be filled in by O.E.M" whatever that means. 
The freezing is intermittent, sometimes it freezes in a programme or game (no lights on keys nor mouse when that happens) other times it won't even load windows.  We have just moved house, but I opened it when i changed battery and couldn't see anything "loose" as such.. I have no spare parts to swap stuff out with either as suggested so I guess I will have to save for repair in a store.  Thank you for the suggestions I had this symptom on my PC actually, and I put a new power supply in it and it seemed to solve the problem. Like you, I also experienced some BSODs and then just freezing completely. I moved my computer around a lot too. Not to mention that I took every part I could out of the computer I had and put it back in. So I could have fixed something that I didn't know about. Since you are a novice, I don't recommend you do that. 

One thing to always check is if there are any bloated or busted capacitors on your motherboard.  That helps too.

Have a great day,
Anthony

 
 Just had the Blue Screen with error KMODE EXCEPTION NOT HANDLED  - was wondering if this helps shed any LIGHT on what might be causing my freezing?... A quick search suggests this may be a driver issue.  Depending on settings, Windows will automatically update the drivers for the different hardware in your computer.  If someone releases an unstable driver it can be automatically loaded on your computer. 

If you can get a picture of the next one or send us your dump files, we could try to narrow it down.

From there, we can try to find either a newer version of the drivers or find an old version to revert to that is stable.

 thank you for the reply, I have tried manually checking and updating the drivers. The last blue screen i got was IRQL NOT LESS OR EQUAL.. I ran the windows blue screen troubleshooter but it said no issues (yet its bluescreened 3 times in the past hour)  I think I just need to wait for pay day and take it in some place.  When the error messages are random INSTEAD of consistent it usually points to a flakey PSU...

Don't buy a cheap one.